/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University. All rights reserved.
 * 
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license; 2) All redistributions in binary form
 * must reproduce the above copyright notice, this list of conditions and the
 * disclaimer listed in this license in the documentation and/or other materials
 * provided with the distribution; 3) Any documentation included with all
 * redistributions must include the following acknowledgement:
 * 
 * "This product includes software developed by the Community Grids Lab. For
 * further information contact the Community Grids Lab at
 * http://communitygrids.iu.edu/."
 * 
 * Alternatively, this acknowledgement may appear in the software itself, and
 * wherever such third-party acknowledgments normally appear.
 * 
 * 4) The name Indiana University or Community Grids Lab or NaradaBrokering,
 * shall not be used to endorse or promote products derived from this software
 * without prior written permission from Indiana University. For written
 * permission, please contact the Advanced Research and Technology Institute
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202. 5) Products
 * derived from this software may not be called NaradaBrokering, nor may Indiana
 * University or Community Grids Lab or NaradaBrokering appear in their name,
 * without prior written permission of ARTI.
 * 
 * 
 * Indiana University provides no reassurances that the source code provided
 * does not infringe the patent or any other intellectual property rights of any
 * other entity. Indiana University disclaims any liability to any recipient for
 * claims brought by any other entity based on infringement of intellectual
 * property rights or otherwise.
 * 
 * LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO
 * WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 * NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF
 * INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS.
 * INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS",
 * "VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.
 * LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR
 * ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION
 * GENERATED USING SOFTWARE.
 */
package cgl.narada.matching.regex;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import cgl.narada.event.NBEvent;
import cgl.narada.event.TemplateProfileAndSynopsisTypes;
import cgl.narada.matching.MatchingTree;
import cgl.narada.matching.Profile;
import cgl.narada.protocol.Destinations;
import cgl.narada.protocol.ProfilePropagationProtocol;

/**
 * This class implements the regEx matching algorithm. This provides methods to
 * add a subscription and also to remove interest in a subscription predicate.
 * The matching algorithm should also be able to compute destinations.
 * 
 * @author Shrideep Pallickara $Revision$ $Date$
 */

public class ClientRegExMatching implements MatchingTree,
        RegExMatchingDebugFlags {
    /** Profile Propagation Handler */

    private ProfilePropagationProtocol profilePropagationProtocol;

    /** The unit level for this matching tree */
    private int unitLevel;

    /** The system level */
    private int systemLevel;

    /** The destination for this node */
    Destinations thisDestination;

    /** contains a mapping of destinations associated with a given profile */
    private Hashtable profiles;

    private String moduleName = "ClientRegExMatching: ";


    /** The RegExMatching constructor */
    public ClientRegExMatching(int unitLevel, int systemLevel,
            ProfilePropagationProtocol profilePropagationProtocol) {
        this.unitLevel = unitLevel;
        this.systemLevel = systemLevel;
        this.profilePropagationProtocol = profilePropagationProtocol;
        profiles = new Hashtable();
    }


    /**
     * This method returns the level assocaited with this matching tree. A node
     * could be a gateway at multiple levels. How it handles destinations at
     * different levels, and propagates destinations at different levels is
     * dicatated by the level of the matching tree which computes the
     * destinations and initiates profile propagation changes.
     * 
     * @return The level of the matching tree.
     */
    public int getMatchingLevel() {
        return unitLevel;
    }


    /** This method sets the destination address for this node */
    public void setNodeDestination(Destinations destination) {
        thisDestination = destination;
    }


    /**
     * This method adds a subscription profile to the matching tree
     * 
     * @param profile
     *            The profile comprising the subscription and the destination
     *            assocaited with the subscription.
     */
    public void addSubscriptionProfile(Profile profile) {
        RegExProfile regExProfile = (RegExProfile) profile;
        System.out.println(regExProfile.getSubscription());

        String profileId = regExProfile.getProfileId();

        if (profileId == null) {
            System.out.println(moduleName + "Unacceptable profileID ["
                + profileId + "]");
            return;
        }
        if (profiles.containsKey(profileId)) {
            System.out.println(moduleName + regExProfile
                + "=>>>Already registered");
            return;
        }
        profiles.put(profileId, regExProfile);
        propagateChangesToHigherLevels(regExProfile, true);
    }


    public void removeSubscriptionProfile(Profile profile) {
        RegExProfile regExProfile = (RegExProfile) profile;
        String profileId = regExProfile.getProfileId();
        if (!profiles.containsKey(profileId)) {
            System.out
                .println(moduleName + regExProfile + "=>>>Not registered");
            return;
        }
        profiles.remove(profileId);

        /** Propagate this loss of profile to the highest levels */
        propagateChangesToHigherLevels(profile, false);
    }


    public void removeProfilesForDestination(Object clientIdentifier,
                                             String linkId) {
        if (clientIdentifier == null || linkId == null) {
            System.out.println(moduleName + "ClientIdentifer=["
                + clientIdentifier + "] or LinkId=[" + linkId + "]");
            return;
        }

        int destination = ((Integer) clientIdentifier).intValue();
        Enumeration profileIds = profiles.keys();
        while (profileIds.hasMoreElements()) {
            Object profileId = profileIds.nextElement();
            if (profiles.containsKey(profileId)) {
                RegExProfile regExProfile =
                    (RegExProfile) profiles.get(profileId);
                if (regExProfile.getDestination() == destination) {
                    profiles.remove(profileId);
                    /** Propagate this loss of profile to the highest levels */
                    propagateChangesToHigherLevels(regExProfile, false);
                }
            }
        }
    }


    public void propagateChangesToHigherLevels(Profile profile,
                                               boolean addProfile) {
        if (profilePropagationProtocol == null) {
            return;
        }

        RegExProfile regExProfile = (RegExProfile) profile;

        /**
         * The first step ofcourse is to replace lower level destinations with
         * the destination ID at the next higher level
         */
        if (ClientRegExMatching_Debug) {
            System.out.println("The destination associated with profile "
                + regExProfile.getSubscription() + " is "
                + regExProfile.getDestination());
        }
        int temp = 0;
        int tempDest;
        for (; temp <= systemLevel;) {
            tempDest = thisDestination.getDestinationsAtLevel(temp);
            if (ClientRegExMatching_Debug) {
                System.out.print("This destination would be replaced by "
                    + tempDest);
            }
            
            if (ClientRegExMatching_Debug) {
                System.out.println(" for representation in a level(" + temp
                    + ") tree ");
            }

            RegExProfile _propagateRegExProfile =
                new RegExProfile((String) regExProfile.getSubscription(),
                                 tempDest, regExProfile.getProfileId());

            profilePropagationProtocol
                .propagateProfileChange(_propagateRegExProfile, temp,
                                        addProfile);
            temp++;
        }
    }


    /**
     * This method return the destinations assocaited with an event that needs
     * to be matched to the matching tree
     * 
     * @return The destination as an INT
     */
    public Object matchEvent(NBEvent nbEvent) {
        String contentSynopsis = (String) nbEvent.getContentSynopsis();
        Hashtable destinations = new Hashtable();
        Enumeration _profiles = profiles.elements();
        while (_profiles.hasMoreElements()) {
            RegExProfile regExProfile = (RegExProfile) _profiles.nextElement();
            Integer destKey = new Integer(regExProfile.getDestination());
            if (destinations.containsKey(destKey)) {
                continue;
            }
            Pattern regExPattern = regExProfile.getPattern();
            if (evaluateRegExOnInput(regExPattern, contentSynopsis)) {
                destinations.put(destKey, regExProfile);
            }
        } /* end while */

        return destinations;
    }


    public boolean evaluateRegExOnInput(Pattern regExPattern,
                                        String contentSynopsis) {
        Matcher matcher = regExPattern.matcher(contentSynopsis);
        matcher.reset();
        return matcher.find();
    }


    /** Returns the type of profiles managed by this matching engine */
    public int getManagedProfileType() {
        return TemplateProfileAndSynopsisTypes.REGULAR_EXPRESSIONS;
    }


    public static void main(String[] args) {
    }

}
